Piston for internal combustion engines



Aug. 22, 1939. E. E. LEISSN ER PISTON FOR INTERNAL COMBUSTION ENGINES 2 shets-sheet 1 Filed June 12, 1937 INVENTOR.

E. Leissner ATTORNEY.

Aug. 22, 1939. EYE. LEISSNER PISTON FOR INTERNAL-COMBUSTION ENGINES 2 Sheets-Sheet 2 Filed June 12, 1937 Patented Aug. 22, 11539 UNITED STATES PISTON FOB INTERNAL COMBUSTION ENGINES Edward E. Lcissner,

of one-half to York, N. Y.

New York, N. Y., assignor Arthur J. Schossberger, New

Application June 12, 1937, Serial No. 147,813

This invention has reference to pistons for internal combustion engines, and particularly relates to a duplex structure which has many advantages over the ordinary piston in that it cushions the explosive force of the gases and automatically lubricates and cools the walls of the piston and tends, in greater measure, to scavenge the piston casing, bringing about quietude, increased flexibility, efli'ciency, ease and power, as will be hereinafter pointed out.

Among the objects of my invention may be noted the following: to provide a duplex piston, or piston having two heads or parts, one working within the other and provided with means by which the two parts will be caused to coop-' erate in the production of new and the usualfunctions; to provide a duplex piston having interacting parts so constructed as to enable the one part to modify the operation and function of the other part; to provide a cup-shaped piston which carries a supply of lubricant and is causedto automatically lubricate the piston. and adjacent parts during the stroke thereof; to provide a hollow, double-headed piston with self-lubricating and self-cooling means whereby excessive friction and 'wear are avoided and heat is rapidly dissipated; to provide a piston with means by which its action may be cushioned, its operation may be facilitated, its function of cleaning out the chamber in which it works may be greatly improved, and which piston may be both lubricated and cooled; and to provide a piston with simple means which will produce the objects and functions stated and which is cheap to construct and economical to operate. I

With 'the above objects in view and others which will be detailed during the course of this description, my invention relates to the parts, features, elements and combinations thereof hereinafter described and claimed.

In order that my invention may be clearly understood I have provided drawings in which:

Fig. 1 is a view in sectional elevation of a structure embodying my invention;

Fig. 2 is a similar view showing the parts of Fig. 1 in a different position;

Fig. 3 is a detail view, showing a simple means for limiting the movement of the auxiliary pistonhead;

Fig. 4 is a view similar to Fig. 3, showing another form of my invention;

Figs. 5 and 6 are views similar to Figs. 1 and 2 showing other forms of my invention;

Figs. 7 and 8 are views showing details of the 8 Claims (C1. 123-18) pitman mechanism of Fig. 5 in different positions; and Y Figs. 9 and 10 are views showing variant de- -tails of the pitman mechanism of Fig. 6.

Referring to the drawings, the numeral l in- 5 dicates the usual cylinder block or casing within which the piston reciprocates and which is pro;-

-vided with the head 2, cooling Jacket or chambers 3, and a spark-plug indicated at 4, located at any point in the combustion chamber or head 10 thereofwhi'ch is desired, according to the type of engine in which the piston 5 is employed. According to my invention the piston works in the usual cylinder or casing, having a reciprocating action therein imparted by a pitman 6, carried on a wrist-pin I, connected to the pitman so as to impart motion to a usual crankshaft. Located in the diametrlcal center of the piston 5, or approximately so, is a cup, or supplemental casing 8, which carries a supply of lubricant in the sump thereof. The cup is formed integral with the walls of the piston 5, the connection between the two forming at its outer end a piston-head 9 of substantial dimension or large predetermined area. Within the cup- 8 slides an auxiliary piston-head l0 having a skirt or deep circumferential flange H which hugs the inner wall of the cup 8. The cup depends a-predetermined distance within the piston proper and the walls thereof are provided with inclined oil and air apertures l2 which may be staggered circumferentially. Within the cup 8 is located a strong coiled spring 03, preferably angular in cross-section, which sustains the auxiliary piston head "I flush with the outer surface or end 9 of the main member of the piston, or provides a means by which the auxiliary piston-head may be sustained within the main piston as hereinafter described.

In the wallet the piston 9 is provided an external angular groove H, in which is set a ring l5 adapted to engage and limit the movement of the auxiliary piston-head I 0 and prevent its surface being projected beyond the surface or end of the head 9, under the expansive force of the springli. In the form of construction shown in Figs. 1, 2 and 4, the plate or ring is shown angular in cross-section and is sweated, threaded main piston and driven in a spray from the latter auxiliary piston is limited in its outward movement by a shoulder "lb and the ring ii shown- V the sleeves 2|,

into the space surrounding the oil retainer. Betweenthewall oithemainpistonpartand the wall of the cup-shaped part of the piston there is a circular chamber is providing a cooling space for the various walls of the piston in addition to the cooling jacket 3 of the engine which has a like function. The cup-shaped member of the main piston part, in the apertures provided for the ingress and egress of oil and air, is preferably provided with shields 20, formed on the end of which are swaged or otherwise forced into the apertures l2, this structure being conceived to be a ready means for momentarily retaining particles or an accumulation of oil which may be condensed or cling thereon from the spray produced in the chamber It, or which may be forced from the sump of the cup 8. It

will be understood that the chamber I! will be subject to the'flne mist of oil produced as the result of the usual splash system; and it will be seen. that when the auxiliary piston-headis forced inwardly oil and air will necessarily be driven outwardly into the chamber is, and when the piston-head I. is forced outwardly by the action of the spring IS, the particles of oil which may have collected and the air will be sucked into the chamber with a cooling eil'ect and the oil will find its way to the sump 22 at the bottom of the cup-shaped member ofthe main piston, the inner and outer walls of the cup, and the spring contained therein will be supplied, and the air will cool the parts.

Obviously, oil will be supplied to the sump 22 before the parts are assembled.

The auxiliary piston-head may occupy a major or minor or equal portion of the diameter of the main piston-head; but I have shown the impact surface of the auxiliary piston-head to be less than the impact smiace of the main piston-head. As to this I do not purpose being limited as the proportions of the two piston-heads may be varied, my invention in this regard residing in havingthe auxiliary piston yielding relatively to the main piston.

In the form of Fig. 6, the domed head of the in Figs. 1 to 5, and the inward movement of the piston Ila will have the function of forcing oil and air through the apertures l2 and from the shields II, and if the valve It happens to be open both oil and air will be forced therefrom. On the other hand. when the piston Illa is forced outwardly by the spring ii, there will be a suction eflect from the space I! of the piston-head 9, of both air and oil. The space of the dome la 70,

of the auxiliary piston will lend a cooling effect to said piston. V V

The spring I3, in the chamber of the main piston, is selected with reference to its ability to sustain the auxiliary piston and prevent the latter from being driven too far or too precipiauaaoo I r I tate ly into the cup-of'the main piston; and is shown made angullrin cross-section because of strength, its greater superficial area and ability toavoid shifting under action. p I

Instead of depending upon .the pumping action of the auxiliary piston, per se, for lubrication and cooling the various parts, I may provide the cup I with one or more small pumps located on the bottom thereof and actuated by cams or projections 23 on the sleeve or head 24 of the pitman 6, said means actuating a piston 25, working in a casing projecting from the bottom of the cup I and lifting a spring-controlled valve 26, within said casing of the cup and spraying the oil standing in the sump thereof, tending to atomize the same and project it through the apertures I2. These pumps may be actuated alternately as the main piston is actuated, the oscillation of the pitman resulting in reciprocating the valves of the pumps. This operation will take'effect each time the auxiliary piston Ill moves either in or out under the explosive action of the gas or of its spring l3.

As shown, the small piston 28, carrying the valves 16 are mounted in the casing 25a, provided with the ports I! communicating with the sump 22. The ports 25b of the casing connect with the passage 25c extending lengthwise of the piston 26 to the chamber lid in the casing 25a containing the spring 26a, which sustains the valve 26, the latter having a stem 28b guided in an aperture 260 of the piston. This structure is shown in detail at the right hand side of Fig. 2,

- where the partial section shows that, as the pitman 8 moves downwardly, and from its highest position, and rocks over from the position of Fig. 2 into the position at the extreme right, one of the cams 23 moves upwardly, the spring 28a,

and II, and thence be sprayed into chamber I! through the apertures l1. A small residue will find its way into the sump 22. In Figs. 1 and- 2,

I have shown two pump structures, such as described, actuated alternately by the cams 23, extending from the head of the pitman 6.

It will now be apparent that I consider it highly important and that it is the gist of my invention, to provide a structure which will give a cushioning eflect tothe piston and at the same time adequately' provide for cooling and lubricating the various parts of the piston and its surroundings. I have accomplished these functions by the mechanisms above described; but, they may be accomplished in various ways as shown by the following:

1 In Fig. 5 I have shown another form of my invention wherein the oil and the air are pumped into and out of the cup 8 and operated by the auxiliary piston II; that is to say, I have provided the bottom of the cup. with a mound In which in turn is provided with an aperture 21. This produces a sump in the central part of said cup and with this aperture 21 cooperates a cam or projection 28 on the member I or end of the pltman 62' The projection 28 is in the form of a cam and during the oscillatory action of the pitman 6 the said cam is caused to open and close the aperture 21 due to the position of the pitman and the crank operated thereby. In this form.

of my invention it will be seen that when the piston-head i0 is depressed the projection or cam 28 will be caused to shift either to the right or left, as the case may be, viewing Figs, 5, 7 and 8, and when the piston I0 is projected outwardly under the spring impulse the cam 23 will close the aperture 21 so as to .prevent oil or air from entering the chamber or cup of the piston .5. To

prevent the air contained in the cup 8 from retarding the action of the piston In a small tube 21a is inserted in the bottom of the cup-8 which operates as a vent on the downward movement of the said piston l0, thus avoiding any retardation which might result as the air is forced outwardly from the cup 8 and which will not be' taken care of by the tubular vents I2. The dotted line representation in Fig. 5 shows that the cam 28 in one position of the pitman 6 will be moved entirely away from the aperture 21 as in Fig. 7. This construction will act as a pump so that on the downward movement of the piston i ll both air and oil will be forced into the chamber IQ of the main piston through the aperture 21 and also through the shields 20 and on the return stroke the aperture 21 will be closed so that the pumping action is restrained, or suction through the aperture 21 cannot occur. In Fig. 8, the reverse effect is shown and dependence is had upon the apertures l2 and shields. 20, regardless of the position of the auxiliary piston l0.

In Fig. 6 I have shown another form of my invention wherein a valve 29 is seated upon a central projection 30 on the bottom of the cup 8 and said valve will be opened and closed by a double-grooved cam carried on the head 1 of the pitman 6 This operation is caused by an antifrictional .roller 3i actuated by the cam parts 32 which will act to compress the spring 33 carried by the stem 34 of the valve 29, which also sustains the anti-frictional roller 3| and holds 3 I with the main head, Figs. 1, 2 and 5, and the will be assumed when the pitman is in the extreme lower position and the roller 3| is between the two cam parts 32, either of said cam parts acting momentarily to lift the valve 29 off its seat at 30. The downward stroke of the piston Ilia, which is simultaneous with the down-stroke of the pitman 6 will cause the other one of the cam parts 32 to engage the antifrictional roller 3|, raise the stem 33 and the valve 29 carried thereby. This downward stroke of the piston Ilia results in compressing the spring i3 and forcing the air and oil within the cup 8 in a spray outwardly through the opening under the valve 29 and the apertures |2-2|| in the walls of the cup 3. In both Figs. 5 and 6 the dotted line position shows the valve or pump open while the full line position of the pitman 5 shows the valve closed and prevents any spraying of oil or air into the chamber l9, through said valve.

In Fig. 9 I have shown the valve 29 open and the roller 3| running in the groove of cam part stroke of pitman 6 the low part of cam 32 will be in contact with roller 3| and the valve 29 be closed. In Fig. 10 I have shown reversed the cam 32, resulting in the valve being closed when the roller 3| is on the low part 01' the cam 32 and the pitman 6 is on the upstroke. In other words, I have shown a means by which the valve 29 can be controlled regardless of whether the piston Illa is raised or lowered, and the result is that the piston lia can be made toexude oil and air, to lubricate and cool the parts, regardless of whether the valve 29 is open or closed. Practical ly the same result can be accomplished with the construction of Figs. 5, 7 and 8, because oi the relatively which, due to the spring l3, will yield and cushion the blow or force on the piston as a whole and avoiding the shock,-also storing energy in the spring l3, and forcing air and oil through apertures |220 into the chamber i9, or causing the pump'to do the same thing due to the action of the cams or projections 23 on' the pitman ring 24, Figs. 1 and 2. As the piston 9 starts to return, the auxiliary piston is returned by the spring [3 and the two pistons scavenge the combustion chamber of the cylinder, the auxiliary piston having the function of completing the scavenging by. removing as nearly as possible all particles of combustion remaining in the piston chamber of the cylinder or any accumulation on the two heads. When the intake action begins the spring i3 will have completely returned the auxiliary head to position flush the cup or inner cylinder, thusdrawing in oil from the surroundings and creating ample lubrication not only for'the frictional surfaces of the cup and auxiliary piston, but also for the spring contained within the chamber.

will also tend to cool the pistons and cushion the action of the auxiliary pistons.

The apertures in the cup be distributed upon the cylinder thereof in more or less of a staggered relation, thus distributing the lubricant .upon the inner and outer walls of the cup and inner walls of the surface of the auxiliary piston. As the piston as a whole operates, the auxiliary piston acts to pump both oil and air and lubricates and cools the walls of-both pistons.- Par- 'ticles of the products of combustion will be thrown off should any tend to occur on or between the piston heads, thus thoroughly and quickly scavenging the combustion chamber. The duplex head of the piston materially absorbs and softens the impact of the expansive force of the explpding gases and produces a smooth running engine. Heat is rapidly dissipated as the result of the hollow chambered head of thepiston and cooling is greatly facilitated.

In Figs. 1 and 2 I have hown auxiliary aper- The structure f to 4 tures 85 extending fromthe all p 22, through the walls, of thepiston '9, so that oil forced outwardly from the sump 22 of the cup F8 will lubriof the explosion upon the head of the cylinder it or its and also upon the head of the piston 9, I have provided a plurality of braces it between the cup d and the exterior wall of thepiston e. These braces y be an integral part of the cup and piston, or may be provided periodically between the wall of piston 9 and the wall or cup d. This provision prevents the force of the explosion from jarring and possibly cracking thecup it in any event.

From the foregoing description, it will be seen that, among other things, it'ls the gist of my invention to provide a means by which either the explosion chamber above the piston head can be actually made smaller, or the piston heads can be raised so as to reduce the size of the explosionchamber. This results in more fully exhausting the dead gases and in a higher compression of the gases preliminary to explosion. I have overcome the knock produced in most engines by providing the auxiliary piston, which yields and cushions the explosive force of the gases. In time way, I have also provided a means for more eiiectively clearing the explosion chamber on exhaust.

While I have shown my invention as applied to a four-cycle engine of the internal combustion type, I desire it to be clearly understood that it is also applicable to a two-cycle engine, or an engine of the Diesel type. In other words, it is my efiiort to produce an engine or high-compression and increased scavenging ability. And in. the drawings, while I have shown only a single type of engine, I desire it understood that other types can be utilized with equal facility and emciency. It will be understood that it is my effort to provide a high-compression engine and that this can be accomplished either by increasing the size or area or the piston'hea'ds, or reducing the size or area of the compression chamber, or increasing the throw of the crank, and/or increasing the throw of the pitman or connecting rod. In any event I will bring about and produce in my engine and with the means shown and suggested increased scavenging, increased power and an increase of the cushioning effect of the piston or pistons.

It will also be seen that I may produce a closed chamber in the piston by the elimination of the valves 25-26, or by the elimi na:tion or the aperture 27 and the means for controlling the same, or by doing away with the valve structure of Figs. 6, 9 and 10; or so controlling each of these means, valves or pumps as to produce in the piston head a finite chamber which may be caused to bring about a substantially closed chamber and produce and control the cushioning effect of said piston head, or of the engine as a whole. By the means suggested I desire to accentuate the fact that Iwill increase the power, efficiency, the scavenging effect and especially the cushioning effect or the piston and allied parts, or associated parts.

Having described my invention, what I claim '1. In an internal combustion engine, a hollow, double-headed piston having a pump for sucking air and oil, thereby dissipating the heat thereof.

2. In an internal combustion engine, a piston having within said walls an oil-cup, and. means for discharging oil therefrom.

3. In an internal combustion engine, a piston having within its circumference a cup-shaped member providing an enlarged space adapted to contain oil, and means for spraying said oil, thereby tending to cool the walls or the pistons.

i. In combination, a main piston head having an inwardly extending oil-carrying cup-shaped cavity spaced from the outer wall of said main piston, a secondary piston head operating within the cavity, and means in said cavity, and between V the two heads whereby they may yield relatively to each other for cushioning the impact of the gases upon both pistons,and for aiding in scavenging the cylinder of the engine and itself.

5.1m combination, a duplex piston carrying a pump whereby oil may be distributed within the piston and whereby air may be combined with the oil for cooling the piston.

6. In combination, a main piston head and an auxiliary piston head carried the one by the other, means for actuating the two piston heads, a pump carried by one of'the piston heads, and means on the piston actuating means for actusting the pump.

7. In combination, 'a' main piston head and an aumliary piston head carried the one by the other, one of the heads being providedwith a cooling and oiling means, which positively lubricates the main and auxiliary piston heads and the chamber in which they work.

8. In combination, a main piston head and an auxiliary piston head carried the one by the other, one of the heads provided with a cooling and oiling means and means including a cam operating to actuate said cooling and oiling means carried by the pitman for controlling th crank of the engine. 

